1. Field of the Invention
The invention relates to skip stitch sewing machines which include needle bar latching and releasing mechanisms.
2. Description of the Prior Art
Skip stitch mechanisms, such as shown for example, in U.S. Pat. No. 3,782,311, of Kenneth D. Adams and Salvatore A. D'Orio for "Simplified Basting Stitch Mechanism" issued Jan. 1, 1974, and in U.S. Pat. No. 4,312,284, of Kenneth D. Adams for "Needle Bar Deflecting Arrangement for a Skip Stitch Sewing Machine" issued Jan. 26, 1982, include a normally engaged needle bar latch which is opened whenever the needle bar is jogged by a gate to a predetermined maximum lateral position on one side of a central needle bar position. The needle bar is thereby disconnected from actuating mechanism for imparting endwise reciprocatory motion thereto and a skipped stitch results. When the latch is opened to disconnect the needle from the actuating mechanism, the needle bar is drawn upward by an elevating spring into a limited position defined by the engagement of needle bar affixed structure with a fixed cantilevered cushioning spring. The cantilevered cushioning spring engaged the needle bar affixed structure at a location which is off-center with respect to the needle bar axis. As a consequence, the needle bar was loaded unsymmetrically, and undue noise was generated in the needle bar supporting bearings and in needle bar actuating mechanism. Further, the cantilevered spring had a high spring rate and this was responsible for considerable noise being generated whenever the needle bar returned to its uppermost position.
It is a prime object of the present invention to provide an improved arrangement for cushioning upward movement of an unlatched needle bar into an extreme position in a skip stitch sewing machine.
It is another object of the invention to provide an improved arrangement in a skip stitch sewing machine for applying a cushioning force to an upwardly moving unlatched needle bar released while in a maximum lateral jogged position from actuating mechanism.
It is still another object of the invention to provide skip stitch sewing machine mechanism with a needle bar cushioning spring which is inexpensive to produce and can be easily assembled in a machine.
It is also an object of the invention to provide a needle bar cushioning spring arrangement which is effective in sewing machines to minimize noise due to the operation of skip stitch mechanism.
Other objects and advantages of the invention will become apparent during a reading of the specification taken in connection with the accompanying drawings.